Implants allow man to operate prosthetic

The Philadelphia Inquirer

Published Thursday, July 13, 2006

With the aid of electrodes implanted in his brain, a man paralyzed from the neck down was able to perform certain everyday activities -- move a computer cursor, open e-mail, turn on a TV set -- merely by imagining them.

The patient, whose spinal cord was injured when an attacker stabbed him in the neck, was even able to open and close a prosthetic hand, his thoughts translated into action by a custom-built computer.

For now, the patient must be tethered to a cart loaded with electronics. The system was developed by scientists at Brown University, who say it is just a few years away from commercial use.

The results, reported in today's issue of the journal Nature, offer hope that thousands of people with injured spinal cords could someday regain significant function by simply bypassing the injury. Eventually the team expects patients will have a wireless device implanted in the brain that sends signals not just to computers, but to parts of their own bodies.

Coincidentally Wednesday, a team that includes Drexel University scientists reported progress toward a similar goal in lab rats, albeit by different means. The researchers removed a nerve from each animal's leg and transplanted it across the injured spinal cord, restoring some mobility to paralyzed forelimbs.

Meanwhile the efforts of the Brown University team, which included researchers in Chicago and Massachusetts, seem like something out of science fiction.

After implanting electrodes in the brain of Matthew Nagle, the 25-year-old stabbing victim, scientists discovered that the neurons associated with moving his arms and hands could still generate electrical signals -- a surprising find, three years after the attack.

They ran wires through his skull to BrainGate, an electronic device that filtered out the noise and learned to interpret the signals. When connected to a computer, Nagle was able to play the video game "Pong" and also drew a circle using a computer drawing program.

"I just imagined moving the cursor," he said in a telephone interview, from his room in a Massachusetts rehab hospital.